Various approaches to creating environmentally-friendly packaging and to reducing packaging costs are known. One approach is to reduce the materials used to form the package. For instance, consumer articles typically are packaged in a primary package (directly containing the article, such as a bottle which contains a fluid or solid form), which primary package is then placed in another, secondary package (such as a paperboard or cardboard box). Typical primary packaging for consumer articles have curved or rounded side walls, whereas typical corresponding secondary packaging has flat side walls. Thus, the outer surface area of the secondary packaging typically is greater than that of the primary packaging, and greater than necessary simply to enclose the primary packaging. A more environmentally-friendly approach to packaging reduces or even eliminates the secondary packaging. However, secondary packaging is often beneficial for providing product information about the article contained within the primary packaging, as the primary packaging often does not provide enough outward surface area to display all the information about the article typically desired by consumers, or required by federal agencies. For instance, various over-the-counter (non-prescription, or “OTC” for short) consumer articles, such as OTC drug products, are regulated by the Food and Drug Administration (FDA), which, as an agency, requires specific product information, such as the statement of identity (established name and general pharmacological class), quantity and dosage form, and Drug Facts, to be displayed on the packaging. Drug facts may include, but are not limited to, information on the active ingredient, active ingredient chemical name, active ingredient dosage, uses, warnings, directions, and inactive ingredients. Drug labels are also required to have lot number and expiration dating, and a company contact, which includes manufacturer or distributor information.
Upon eliminating secondary packaging, and packing or stacking together multiple primary packages with typically convexly-curved side walls (typical primary packages for OTC drug products have substantially circular cross-sections), it becomes evident that an excess amount of empty space is generated between the surfaces of the convexly-curved walls of the primary packages that cannot be stacked against one another. One solution has been to use primary packaging with one or more substantially flat side walls, such as a primary package with a quadrilateral cross-section. Such primary packaging, however, may not be as comfortable to hold in the user's hand, particular if the primary package is sized to fit in at least a portion of the palm of the user's hand.
Various primary packages with quadrilateral cross-sections have been designed to be stacked horizontally, i.e., with their longitudinal axes (along which the opening to the primary package and the bottom closed end of the primary package lie) substantially horizontal. Such stackable primary packages are shaped to be laid on their substantially flat side walls, or on side walls that have a flat section for stabilizing the primary package when laid horizontally. Although interlocking or intermeshing features may be provided to inhibit relative lateral shifting of the stacked primary packages, there typically is a need for further lateral stabilization of such stacked primary packages.